I'm wondering whether bacteria and fungi can be present or can grow in drysol: an antiperspirant consisting of absolute ethanol and aluminum chloride hexahydrate. We got some results from a rather unserious foreign lab:

it will hardly be <0 and if it is >0, then there is some growth However, it's always kind of probability numbers, especially for low counts. That's probably also reason, why they do not clearly state 0 cfu/g, but rather give some limit.

It's hard to know what pi87 is asking as the report offers no confdence anything was detected. Agree th 1:10 dilution cited doesn;t seem consistent with the <1000 report. My bet is the diluton factor is stated incorrectly as substantial dilution is necessary to neutralize product carryover. Although one can recover spore forming bacteria and even vegetative bacteria (in biofilm) from ethanol, antiperspirant aluminum Cl salt renders the product very acidic so it's pretty hostile and would require a fair amount of dilution to neutralize.

mostly no microorganism can survive in that environment specially those susceptible or"weak microorganisms".but yes, a spored microorganisms can may survive . cosmetics can be contaminated (mostly yeast and molds) after production, during filling, packaging, the way they handle the cosmetic.Obviously they grow only on the surface of the cosmetic as an indication of contamination.That is why we use the antimicrobial efficacy test/challenge test to determine the efficacy of its preservative.

No - the most common contaminants of cosmetics are bacterial - esp. is Burkholderia cepacia and grow throughout the product. Contamination is most frequently associated with water - poor quality process water or cleaning water such as from failed draining of systems after washoutincubating in equipment inclding those mentioned.

Mold contamination is a relatively rare event in comparison. It is typically limited to the surface of semiolid cosmetics in open jars and is probably as much a consumer as manufacturing issue - so is pretty obvious when it does occur. Yeast contamaintion is also somewhat rare and is not surface limited.

The AET is useful but not insurances. Cosmetic micro quality is as much a function of process hygiene as preservation as bacteria can adapt/ develop tolerance and resistance to any preservative given the right opprtunity.